1. Field
The present disclosure relates to a battery module. More particularly, the present disclosure relates to a battery module provided with a voltage sensor.
2. Description of Related Art
Japanese Patent Application Publication No. 2010-40295 (JP 2010-40295 A) describes a battery module that includes a stacked body formed by an array of a plurality of battery cells, end plates provided one on each end of this stacked body, and restraining bands that restrain the end plates.
In such a battery module, negative terminals and positive terminals provided on the battery cells are connected together by a bus bar, such that the battery cells are connected together in series. Also, a power line is connected to the battery module, and this power line is connected to a power control unit via a SMR (System Main Relay) or the like.
Further, the battery module is provided with voltage sensors that measure the voltage of each battery cell, a voltage detection line that is connected to each voltage sensor as well as to a battery ECU (Electronic Control Unit), a temperature sensor that measures the temperature at a predetermined location of the stacked body, and a thermistor line that is connected to the temperature sensors as well as to the battery ECU. The voltage sensors are typically connected to the negative terminals and the positive terminals of the battery cells.
Here, the power control unit includes a converter and an inverter. The power control unit is electrically connected to a motor. Also, noise generated by the motor, the converter, and the inverter while a vehicle is being driven reaches the battery module via the power line. The noise that reaches the battery module also enters the voltage sensors and the voltage detection line through the terminals of the battery cells.
Further, if the voltage detection line and the thermistor line are provided in positions close to one another, noise transmitted to the voltage detection line will be transmitted to the thermistor line, and as a result, noise will also enter the output of the thermistor line.
In order to inhibit noise from entering the thermistor line in this way, it is conceivable to connect a filter between the power control unit and the battery module, or increase the distance between the voltage detection line and the thermistor line, for example.
However, providing a filter may increase the costs. Also, if the thermistor line is simply distanced from the voltage detection line so that the noise that is superimposed on the thermistor line becomes sufficiently small, the thermistor line may end up being in a position that is also distanced from the battery module, which may create problems for mounting of the battery module.
In the battery module, a current detection line from a current sensor is also provided in addition to the thermistor line, and voltage lower than that of the voltage detection line is applied to this current detection line. If the current detection line is provided close to the voltage detection line, noise from the voltage detection line may also be transmitted to the current detection line.